<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Ranatra Fabricius 1790</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"/> </head> <body> <h2>Key to species groups of Oriental <i>Ranatra</i> Fabricius, 1790</h2> <p>1. Posterior margin of metasternum clearly emarginated..........2</p> <p>– Posterior margin of metasternum convex, or straight or only slightly emarginated................................................................3</p> <p>2. Vertex with prominent tubercle between eyes; siphon relatively short, ratio of siphon length: body length around 0.2–0.7; fore femur at mid-length of flexor side with one tooth and a carina, or bi-dentate................................................... <i>R. gracilis</i> group</p> <p>– Vertex with small tubercle or evenly round without tubercle; siphon long, ratio of siphon length: body length around 0.9–1.1; fore femur at mid-length of flexor side with one median tooth, without carina............................................... <i>R. bilobata</i> group</p> <p>3. Large species, body length at least 37 mm; vertex lower than eye, no tubercle; fore femur at distal 0.3–0.4 of flexor side with one long, narrow tooth; operculum of female clearly surpassing apex of connexivum.................................... <i>R. elongata</i> group</p> <p>– Smaller species, body length at most 34 mm; vertex higher than eye, with small tubercle or without tubercle; flexor side of fore femur bidentate; operculum of female at most reaching apex of connexivum................................................................4</p> <p>4. Flexor side of fore femur with one tooth much larger than the other one; siphon long, at least equal to body length.................................................................................. <i>R. malayana</i> group</p> <p>– Flexor side of fore femur with one tooth slightly larger than the other one; siphon shorter, at most equal to body length....................................................................................................5</p> <p>5. Fore femur relatively broad, with larger tooth situated at midlength of flexor side <i>....................................... R. varipes</i> group</p> <p>– Fore femur slender, with larger tooth clearly situated nearer to distal end of flexor side..........................................................6</p> <p>6. Eye width clearly less than interocular width............................................................................................... <i>R. filiformis</i> group</p> <p>– Eye width about subequal to or greater than interocular width................................................................... <i>R. biroi</i> group</p> </body> </html>